Elevating mechanism



Feb. 8, 1927. 1,616,598

T. E. PRAY ELEVATING MEHANISM Original Filed April 6. 1922 2 Sheets-Sheet 1 Rb. s; 1927.

T.. E. PRAY ELEVATING MECHANISM Original Filed April 6. 2 2 Sheets-Sheet 2 Patented Feb. 8, 192 7.

THOMAS E. PRAY, OF CHICAGO, ILLINOIS, ASSIGNOR TO GOODMAN MANUFACTURING COMPANY, OFCHICAGO, ILLINOIS, A CORPORA'IION OF ILLINOIS.

ELEVATING MECHANISM.

' Original application filed April 6, 1922, Serial No. 550,192. Divided and. this application filed December 30, 1924. Serial No. 758,939. 1

mechanism for raising'and lowering the cutting mechanism and an improved arrangement of tension means coacting with the a toggle mechanism to assist in raising the cutting mechanism from its lowermost position. I

My invention may be best understood by reference to the accompanying drawings, in Which:

Figure 1 is a side elevation of a machine embodying my invention, with the outer-end of the cutter arm omitted;

Figure 2 is a plan view of the machine with the cutting element and supporting plates removed to show the operating mechanism' of the elevating device;

Figure3 is a side view drawn to a larger scale than Figure 1 and showing the truck and elevating mechanism in cross section. This view also indicates indotted lines the position of the cutting element when raised; and

Figure 4 is a detail of the tension means forming aportionof the elevating device.

In the form in which my invention is embodied as illustrated in the drawings, a cutting element 10 is mounted on a truck frame 11, having wheels 12, 12, adapted for engagement with tracks 13. 13. The cutting including a kerf cutting device, draft device, and a motor for operating these devices. In the form illustrated, I prefer to use for the cutting element a shortwall mining machine of a well-known type adapted normally for movement on the mine floor and having a forwardly projecting cutter arm 14 provided with a cutter chain 15 and with a suitable winding drum 16 having a draft cable 17 wound thereon to move the machine angularly as will hereinafter more fully appear. A motor having suitable operative connection with the cutter chain 15 and the winding drum 16 is mounted. in

a fixed pivot on the truck frame.

construction whereby this pivotal movement element may be of any suitable construction.

a casing 18 at the rear endof the cutting element 10. Details of this motor and operative connections need not be described as they form no part of the present inven-- tion. When used on the mine floor, as suggested. the machine slides upon its bottom face 19in the usual manner. I

In the form shown the cutting element is carried on the truck at all times. 'While the machine is being transported from place to place, the cutting element is arranged longitudinally. of the truck body as shown in Figures 1 and 3, but when cutting a kerf the cutting element is swung angularly about Details 'of may be accomplished are shown in Figure 3, in which it will be seen thata pivotal stud 20 is carried at the rear end of the cutting element and preferably integral with the end plate 21 of the motor casing 18. The cutting element rests on' a plate 22 which. plate in turn rests on a bed plate23 forming the top portion of the elevating device which will hereinafter be described. It will be noted that the stud 20 extends throughthe plate 22 and provides bearing to permit angular movement thereof in a substantially horizontal plane. bearing in an'annular plate 24 forming a part of the bed plate 23. The arrangement Said stud also has is such that the cutting element may be 'pivotally moved on stud 20 with respect to the plate 22 and with the bed plate 23. The

plate 22 may also be pivoted on the common" axis of the stud 20 with respect to. the cut ting element and the bed plate 23. 'The forward edge 25 of the plate 22 isapreferably curved and is retained in a guide mem- .ber 26 attached to the forward end of the cutting element. The forward edge 27 of the bed plate 23 is similarly curved and retained in a guide member 28 attached to the plate 22. Suitable nieans for limiting the lateral swinging movement of the cut ting element and plate 22 with respect to the bed plate 23 are provided, as for instance apair of chains 29 and 30.- Theends of chain 29 are connected on hooks31, 32, at the forward end. of the cutting element 10 and the plate 22,- respectively. The ends of chain 30 connect hook 32 on plate 22,'

with another hook '33 on the bed plate 23.

The length of the chains maybe readily adjusted by engaging any one of the links with the hooks as desired, so as to permit any desired angular movement of the cutting element with respect to the truck to cut a predetermined width of room or entry, The elevating mechanism includes a toggle device having as its principal elements a plurality of toggle members 35, 35, pivotally connecting'the bed plate 23 and the truck frame 11 at points 36, 36, adjacent the front and rear of the machine respectively, and a longitudinally movable toggle member 37 adapted to coact with the toggle members 35, 35, to raise the bed plate and cutting element as indicated in dotted lines in Figure 3. This general arrangement of toggle members is similar to that disclosed in my 7' copending application for U; S. Letters Patent, bearingySerial No. 489,763, filed August 4, 1921. v

In the present construction I provide an improved arrangement of tension means co'acting with the toggle mechanism and arranged to be placed under tension by the weight of the cutting mechanism as'it approaches its lowermost position and to assist in the raising of the mechanism from its lowermost position when the toggle members are at the maximum angle with respect to each other and require the greatest amount of power to be operated; This tension device is shown in detailin Figures 2 and 4 and comprises a yoke 40 engaging a movable head 41 of a longitudinally movable rack 42which is pivotally connected at 43130 the toggle member 37. Means for actuating this rack will be hereafter described. A pair of rods 44 are connected to the ends of the yokev 40 and extend into cylinders 45, 45, mounted on the truck member 11. A detail 0f one of these cylinders is shown in Figure 4,'in'whichit will be. seen that the rod 44 is provided at its inner extremity with a collar 46 secured by suitable means such as a bolt 47. the rod: by suitable means such as a pin 49 at a point intermediate the collar 46 and the bearing shoulder 50 at the end of the A smaller collar 48 is fixed on the elevating mechanism in its lowest position, in. which position springs 52 and 53 are under maximum. compression and the movable collar 51 is in. engagement with the fixed collar 4:8,. The spring 52 exerts its pressure. directly on rod 44 through collars 5,1, and; 48, saidispring being of; sufiicient {strength and. stitfznem to. ma ntain pring 53 under full compression. In the initial movement of the elevating mechanism, therefore the full tension of spring 52 is exerted to assist in the upward movement thereof, until the point is reached where the tension of said spring is partially spent, and becomes equal to the tension of spring 53, at which point, both springs become operative and begin toexpand simultaneously, causing collar 51 to move slowly away from fixed collar 49.

During the downward movement of the cuttingmechanism, the action of the springs is manifestly the reverse of that above described, that is tosay, both springs are compressed simultaneously at first, but spring 53, being the lighter, is compressed more rapidly. than spring '52, and collar 51 is brought into engagement with collar 49 before the end of the stroke is reached, so that the final downward thrust of the toggle mechanismis taken up entirely by the heavier spring 52. By means of the arrangement of springs, just described, a maximum tension is provided where it is most needed, at the beginning of the stroke. Springs of varying tensions may be provided to suit requirements asto the weight of the cutting mechanism and power available to lift the same. Two, three or more sets of springs of various sizes and tensions may be provided and the stroke of the springs may be of any length desired. For most purposes, however, it is only necessary to. assist the action of the toggle mechanism through a small portion of its upward movement. In the form herein illustrated, it will be seen in Figures 2 and 3 that. endwise movement of yoke 40 is limited by the cylinders 45, 45, whereas the head 41 of rack member 42 continues its forward movement considerably beyond this p0int,-as shown in dotted lines in Figure 3. The yoke 40 remains inpo'sition to'be engaged by the head 41 when the mechanism is again lowered.

The mechanism for controlling and actuating tie elevating device is shown in Figure '2 and includes a pair of plnions 60, 60,

engaging the rack member 42, and operatively connected to a crank 61 at the rear. end of the truck body 11. This crank is adapted to fit on a squared pin 62. This pin also forms, when coupled at its forward end 62" with the motor shaft64, adriv-i'ng connection between the motor and the truck, for propelling. the latter. lustrated, the machine is propelled only when the cutting element is in its lowermost position, and'the elevating mechanism is inoperative. Furthermore, it is desirable to In the arrangement iloperate the elevating mechanism only when the driving connection between the cutting mechanism and truck is disengaged. Consequently, the handle 61 may be operated t re g he. same ge r-i s. wh ch s; used to propel the truck, so that the elevating mechanism may be actuated Without interfering with the driving mechanism. Details of the elevating and driving mechanism are as follows: I

The squared pin 62 fitsthrough and drives worm 63 which is mounted to turn on a longitudinal axis. WVorm 63 is meshed with Worm gear 64 on shaft 65 mounted on a transverse axis. A second shaft 66 is mounted'parallel with shaft 65 and is driven therefrom through gears 67 and 68. A second gear 69 is carried on the end of shaft 66 opposite gear 68. A transverse driving shaft 70 is mounted adjacent shaft 66, and is provided with chain sprockets 71, 71, keyed on opposite ends thereof and having driving connection with the truck wheels 12, 12. through chains 72, 72; A chain sprocket 73 is loosely mounted on the shaft 7 0, and has driving connection with the pinions 60, 60, of the elevating mechanism through a chain 75, chain sprocket '76 and shaft 77. Further details of the driving mechanism need not be described as they form no part of the present invention, although it may be pointed out that when the truck is not being propelled, andthe driving mechanism is consequently inoperative, the handle 61 may be utilized to raise or lower the elevating mechanism through chain 75 and pinions 60, 60, which operate the rack 42 of the toggle mechanism already described. The worm 63 and gear 64 are of the selflocking type, so that the elevating mechanism may be maintained in any desired position while operating the same. A ratchet device 79 of any suitable construction .is

excepting as it may be particularly limited in the appended claim.

I claim as my invention:

In combination with a toggle'device and means for actuating the same, a tension device comprising a movable member adapted to be operatively connected with said actuating means, two springs of different strengths arranged end to end and interposed between said movable member and a fixed abutment, the lighter spring engaging said movable member, and means limiting the compression of said lighter spring respective to said movable member. a

Signed at Chicago, in the county of Cook and State of Illinois, this 27th day of December, A. D. 1924.

THOMAS E. PRAY. 

